The idea to propose a special issue on time domain electromagnetic (TEM) methods was based on my perception that recent innovations and developments, both in instrumentation and processing, deemed it time to perform a checkup on the state-of-the-art of the method. Many of these advancements address offshore and airborne applications rather than ground-based ones. For example, the popular use of the marine controlled source electromagnetic (MCSEM) method in the oil industry, undoubtedly a real “renaissance” for EM, marked a surge in the development of new devices and approaches, together with the continuous improvement in technology and processing of airborne EM...